Two fluid pump

ABSTRACT

Pumps with housing and a diaphragms located within the housing are disclosed herein. A diaphragm connected to an actuator separates the housing into a first chamber and a second chamber. Each chamber includes a one-way inlet valve and a one-way outlet valve. Movement of the actuator in a first direction causes the volume of the first chamber to contract and causes the first fluid to be expelled from the first chamber while causing the volume of the second chamber to expand and draw in the second fluid through the second one-way inlet valve. Movement of the actuator in the second direction has the opposite effect causing the first fluid to be drain to the first chamber and the second fluid to be expelled through the second one-way outlet valve. The first and second fluid combine in a mixing chamber and form a foam, which is expelled at an outlet.

RELATED APPLICATION

The present invention claims priority to and the benefits of U.S. Provisional Application Ser. No. 61/598,443 titled Two Fluid Pump, which was filed on Feb. 14, 2012, and which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates generally to dispenser systems and a pumping system for dispensing two fluids in the form of a foam.

BACKGROUND OF THE INVENTION

Fluid dispenser systems, such as fluid soap and sanitizer dispensers, provide a user with a predetermined amount of fluid upon actuation of the dispenser. In addition, it is sometimes desirable to dispense the fluid in the form of foam. Foam is generally made by injecting air into the fluid to create a foamy mixture of liquid and air bubbles.

SUMMARY

Exemplary embodiments of pumps are disclosed herein. In some exemplary embodiments, a pump has a housing and a diaphragm located within the housing. The diaphragm separates the housing into a first chamber and a second chamber. Each chamber includes a one-way inlet valve for allowing a fluid into the chamber and a one-way outlet valve for allowing pressurized fluid out of the chamber. An actuator is connected to the diaphragm. Movement of the actuator in a first direction causes the volume of the first chamber to contract and causes the first fluid to be expelled from the first chamber while causing the volume of the second chamber to expand and draw in the second fluid through the second one-way inlet valve. Movement of the actuator in the second direction causes the volume of the first chamber to expand drawing the first fluid in through the first one-way inlet valve and contracts the volume of the second chamber causing the second fluid to be expelled through the second one-way outlet valve. A mixing chamber is in fluid communication with the one-way outlet valves and the first and second fluid combine in the mixing chamber and form a foam.

Exemplary embodiments of dispensers include a dispenser housing and a pump system. The pump system includes a housing and a diaphragm. The diaphragm separates the housing into two chambers. The diaphragm has a first position that reduces the volume of the first chamber and expands the volume of the second chamber. In addition, the diaphragm has a second position that expands the volume of the first chamber and reduces the volume of the second chamber. Movement of the diaphragm to the first position causes fluid to be expelled from the first chamber and fluid to be drawn into the second chamber; and movement of the diaphragm to the second position causes fluid to be expelled from the second chamber and fluid to be drawn into the first chamber.

Exemplary methodologies for creating a foam may include providing a pump having a first chamber and a second chamber separated by a diaphragm. Providing a first fluid comprising an acid and a second fluid comprising a base. Moving the diaphragm to a first position causing the first fluid to be pumped to a mixing chamber and the second fluid to be drawn into the second chamber; and moving the diaphragm to a second position causing the second fluid to be pumped to the mixing chamber and the first fluid to be drawn into the first chamber. A chemical reaction occurs between the first fluid and the second fluid that causes the formation of gas and the mixture is expelled as a foam.

Exemplary embodiments of refill units are also provided. One exemplary refill unit for a two fluid foam dispenser includes a first reservoir and a second reservoir formed between two sheets of material and a first tube extending to the first reservoir and a second tube extending to the second reservoir. The first tube and second tube are at least partially surrounded by the sheets of material. A mixing chamber is included wherein the mixing chamber is in fluid communication with the first and second tubes. An outlet nozzle is located downstream of the mixing chamber. First fluid from the first fluid reservoir and second fluid from the second fluid reservoir are combined in the mixing chamber and form a foam that is dispensed out of the nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will become better understood with regard to the following description and accompanying drawings in which:

FIG. 1 illustrates an exemplary pumping system 100 in accordance with one embodiment of the present invention.

FIG. 2 illustrates the pump of the exemplary pumping system 100 in a first pumping and priming position;

FIG. 3 illustrates the pump of the exemplary pumping system 100 in a second pumping and priming position;

FIG. 4 illustrates a dispenser having an embodiment of an exemplary pumping system; and

FIG. 5 illustrates a foam dispensing system having another embodiment of a two fluid pump.

DETAILED DESCRIPTION

FIG. 1 illustrates a schematic view of a pumping system 100. Pumping system 100 includes a pump 101. Pump 101 has a housing 102. Housing 102 is divided by diaphragm 104 into a first chamber 112 and a second chamber 114. Diaphragm 104 may be made with any flexible material, such as, for example, a thin elastomeric material, plastic, rubber, or even a thin piece of metal. An actuator, such as, for example, piston 106 is connected to diaphragm 104 and extends through housing 102. A sealing member 108 forms a fluid tight seal between piston 106 and housing 102. The pumping system may be used in a wall-mounted dispenser, a tabletop dispenser or a personal hand held dispenser.

First chamber 112 has a one-way inlet valve 120 to allow a first fluid into pump 101 and prevents fluid in first chamber 112 from flowing out of first chamber 112. First chamber 112 also includes a one-way outlet valve 140 to allow fluid to flow out of first chamber 112 through tube 142 and into mixing chamber 144. Similarly, second chamber 114 includes a one-way inlet valve 130 for allowing fluid into second chamber 114 and a one-way outlet valve 146. One-way outlet valve 146 allows fluid to flow out of second chamber 114 and through tube 148 and into mixing chamber 144. The one-way inlet and outlet valves above may be any type of one-way valve, such as, for example, a mushroom valve, a flapper valve, a plug valve, an umbrella valve, a poppet valve, a duck bill valve, etc. An outlet nozzle 150 is located downstream of the mixing chamber for dispensing foam formed by combining the two fluids. In some embodiments, outlet nozzle 150 contains a series of baffles (not shown) to increase the mixing turbulence as the two fluids pass through and are mixed together. In some embodiments the nozzle is narrow and elongated causing the two fluids to mix together.

Pump system 100 also includes a first fluid reservoir 124 for holding a first fluid and a second fluid reservoir 134 for holding a second fluid. First fluid reservoir 124 is in fluid communication with first chamber 112 through tube 122 and one-way inlet valve 120. Second fluid reservoir 134 is in fluid communication with second chamber 114 through tube 132 and inlet valve 130. In one embodiment, pump 101 connects directly to first and second fluid reservoirs 124, 134. Optionally, the system is inverted and pump 101 connects directly to first and second fluid reservoirs 124, 134, and tubes 122 and 132 may not be needed because the fluid flows into the first and second chambers 112, 114 due to gravitational forces. In one embodiment, first and second reservoirs 124, 134 are collapsible and tubes 122, 132 are not needed as vacuum pressure draws the fluid out of the reservoirs.

FIGS. 2 and 3 illustrate pump 101 in operation. In FIG. 2, piston 106 is moved inward and diaphragm 104 deflects inward. In this position, the volume of first chamber 112 is reduced which causes one-way inlet valve 120 to be in a closed position, and forces fluid within first chamber 112 to be expelled out of one-way outlet valve 140. At the same time, the volume of second chamber 114 expands creating a vacuum in second chamber 114. The vacuum causes one-way outlet valve 146 to be closed and draws fluid from second fluid reservoir 134 in through one-way inlet valve 130.

Conversely, when piston 106 is moved outward, diaphragm 104 deflects outward (illustrated in FIG. 3) which causes the volume of first chamber 112 to expand closing one-way outlet valve 140 and drawing fluid from first reservoir 124 in through one-way inlet valve 120. The volume of second chamber 114 is reduced causing one-way inlet valve 130 to be closed and forces fluid out through one-way outlet valve 146.

Referring back to FIG. 1, the first fluid flows from the first chamber 112 through tube 142 and into mixing chamber 144. The second fluid flows from the second chamber 114 through tube 148 into mixing chamber 144. When the first and second fluids combine, a chemical reaction takes place. The chemical reaction causes the fluid to foam, and the foam is expelled out of nozzle 150. In one embodiment, the first and second fluids enter the mixing chamber 144 at an intersecting angle with respect to each other so that the fluids collide together. In one embodiment, the angle is between 30 and 180 degrees.

In addition, in one embodiment, the opening into the mixing chamber 144 from tubes 142 148 restricts the flow of fluid so that the velocity of the first and second fluids is increased as they enter mixing chamber 144.

In one embodiment, the first fluid includes weak acid and the second fluid includes a weak base. When the two fluids combine, a gas is formed. In addition, one or both of the fluids may contain a wax. The gas created by the combination of the two fluids mixes with, and is trapped in, the wax and forms a thick foam.

Pump 101 made in accordance with the present invention may be any suitable size. In one embodiment, the pump 101 is large enough to move a suitable amount of fluid in a small amount of cycles. Such a pump may be operated at a low frequency.

In one embodiment, pump 101 is small and is operated at a high frequency moving a small volume of each liquid into the mixing chamber 144 with each stroke. The rapid movement of small volumes of liquid causes a more violent mixing of the two liquids in mixing chamber 144. In one embodiment, the frequency that pump 101 cycles is greater than about 30 cycles per second and in another is greater than about 60 cycles per second. Although embodiments of large pumps have been described having lower cycle frequencies than smaller pumps, larger pumps with higher cycle frequencies and smaller pumps with lower cycle frequencies are also contemplated herein.

Actuator 106 may be moved electrically or mechanically. In one embodiment, an electric motor rotates a gear and the rotational motion is converted into a reciprocating linear movement to move the piston 106 back and forth. The electric motor may operate of an alternating current source, such as 120 VAC or a direct current source, such as 6 VDC, and may be battery operated. In one embodiment, a manual push bar attached to appropriate gearing converts a linear motion to a rotational motion and to a reciprocating motion to move piston 106 back and forth. The gearing may be such that a relatively short stroke is converted into a large number of reciprocating cycles.

FIG. 4 illustrates a dispenser 400 having a pump 401. Pump 401 is similar to pump 101. Pump 401 has a housing 402 that includes a diaphragm 404 separating the housing 402 into a first chamber 412 and a second chamber 414. First chamber 412 includes a first one-way check valve 420 that is in fluid communication with a first fluid reservoir 424. First chamber 412 also includes a first one-way outlet check valve 440. Second chamber 414 includes a second one-way check valve 430 that is in fluid communication with a second fluid reservoir 434. Second chamber 414 also includes a second one-way outlet check valve 446. A mixing chamber 444 is in fluid communication with first chamber 412 via tube 442 and is in fluid communication with second chamber 414 via tube 448. An outlet nozzle 450 extends from mixing chamber 444 through housing 402 so that the foamed liquid may be dispensed.

Pump 401 also includes an actuator, such as, for example, piston 406. Piston 406 extends through pump housing 402. A seal 408 is provided between piston 406 and housing 402 to prevent fluid from flowing out of the pump housing 402. Piston 406 is connected to an electric motor 450 and gearing 452 through linkage 454. Electric motor 450 may be an AC motor or a DC motor. Preferably, electric motor 450 is battery operated and dispenser 400 includes a battery pack (not shown) for operating pump 401. Movement of piston 406 in a first direction pumps a first fluid from first chamber 412 into mixing chamber 444 and draws a second fluid from second fluid reservoir 434 into second chamber 414. Movement of piston 406 in a second direction pumps the second fluid from second chamber 414 into mixing chamber 444 and draws the first fluid from first fluid reservoir 424 into first chamber 412. When the first fluid and second fluid meet in mixing chamber 444, a chemical reaction occurs causing the mixture of the first fluid and second fluid to form a foam. The foam is dispensed through nozzle 450. An actuator (not shown) is used to actuate the dispenser. The actuator may be a mechanical actuator, but preferably is an electronic actuator and dispenser 402 is a hands free dispenser that detects an object and dispenses foam.

Rather than using electric motor 450 to operate pump 401 of dispenser 402, a manual operator, such as, for example, a push-bar connected to a rack and pinion gear system (not shown), may be used. In one embodiment, a push-bar is connected to a rack that moves in a linear, back and forth motion when the push-bar is pushed and released. As the rack moves forward, the rack rotates a gear which translates the motion to a reciprocating back and forth motion to drive the pump 401. In one embodiment, a spring is used to return the push-bar back to its rest position and causes the gear to rotate in the opposite direction continuing to reciprocate in a back and forth motion to drive pump 401.

FIG. 5 illustrates another embodiment of a foam dispensing system 500 using two pumps to pump fluid that combines to form a foam. Foam dispensing system 500 includes a dispenser housing 502. Located in and about dispenser housing 502 is an actuator and roller (not shown). In operation, the actuator causes the roller to roll down tubes 520 and 522 to force liquid down through the tubes 520, 522. An example of such an actuator and roller system is shown and described in co-pending U.S. Non-Provisional Application Ser. No. 13/605,171, filed on Sep. 6, 2012, which claims the benefits of and priority to U.S. Provisional Patent Application No. 61/531,935 filed September 7, 2011. Both of which are entitled WIPER FOAM PUMP, REFILL UNIT & DISPENSER FOR SAME. These applications are incorporated herein by reference in their entirety. Other actuators such as those shown and described in U.S. Pat. Nos. 7,281,643, 6,189,740 and 5,464,125, which are incorporated herein in their entirety, may also be modified to compress the tubes 520 and 522. The roller (not shown) rolls down tubes 520 and 522 along area A, or the tubes 520 and 522 are compressed from their upper portions downward by other means. Area A may be made longer or shorter. In some embodiments, at least a portion of area A includes tubes 520, 522 and material used to form reservoirs 514 and 516 described in more detail below.

Dispenser 500 includes a refill unit 508 that includes fluid reservoirs 514, 516, fitments 518A, 518B, tubes 520, 522, one-way check valves 530, 532, mixing chamber 524 and outlet 526. In one embodiment, refill unit 508 is made from two sheets of material, such as, for example, LDPE, HDPE, Polypro, Vinyl, EVA, PLA or HDPE. The two sheets of material are welded together as illustrated by the shaded areas 512. Fitments 518A and 518B are welded to the two sheets. Prior to welding, or prior to completing the welding of the two sheets, tubes 520 and 522 are positioned through fitments 518A and 518B and between the two sheets so that when the sheets are welded in the area designated by A, tubes 520 and 522 are surrounded by the sheet material. The sheets are welded to form two chambers 514, 516. Chambers 514, 516 are illustrated as slightly different sizes; however, they may be made equal in size or proportionate to the desired mix ratio of the two fluids. Similarly, tubes 520, 522 may be the same size or different sizes depending on the desired mix ratio. Ends 521, 523 of tubes 520, 522 (respectively) extend up to reservoirs 514, 516. In one embodiment, ends 521, 523 extend up into reservoirs.

In one embodiment, one-way valves 540 and 542 are also included. They are located in tubes 520, 522 near ends 521, 523, respectively. The one-way check valves described herein may be any type of one-way valve, such as, for example, a mushroom valve, a flapper valve, a plug valve, an umbrella valve, a poppet valve, a duck bill valve, etc. These one-way check valves 540, 542 allow liquid to flow from reservoirs 514, 516 into tubes 520, 522, but not from tubes 520, 522 back up into reservoirs 514, 516. The addition of these one-way check valves allows liquid to be pumped through the tubes 520, 522 even if the tubes 520, 522 are not fully compressed by the roller or other mechanism for forcing fluid down tubes 520, 522. In this embodiment, as long as some compression of tubes 520, 522 occurs, the volume within tubes 520, 522 is reduced and fluid is pumped into mixing chamber 524.

Located at the other end of tubes 520, 522 are valves 530, 532 and mixing chamber 524. Valves 530, 532 have a cracking pressure sufficient to prevent fluids from chambers 514, 616 from unintentional discharge. Valves 530, 532 open under sufficient pressure created by the roller (not shown) or other mechanism that forces fluid down tubes 520, 522. A nozzle 526 is located downstream of mixing chamber 524 and extends through housing 502 to dispense foam. In one embodiment, not shown, the roller in its rest position at the upper end of travel is positioned against tubes 520, 522 with sufficient force to pinch the tubes 520, 522 shut and provide additional insurance against unintentional discharge. In one embodiment, a shipping cap not shown is connected to nozzle 526 to prevent unintentional discharge during shipping.

In one embodiment, valves 530, 532 cause fluid to accelerate as it passes through the valves 530, 532 to cause the two fluids to violently collide inside the mixing chamber 524. In one embodiment, the fluid inlets to mixing chamber 524 are positioned so that the fluid streams converge with each other in mixing chamber 524.

While the present invention has been illustrated by the description of embodiments thereof and while the embodiments have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. For example, an air pump may be added to the system to force air into the mixing chamber to further enhance the foam. In one embodiment, first chamber 112 and/or second chamber 114 may be configured with a second one-way inlet valve (not shown) allowing the first chamber 112 and/or second chamber 114 to draw in fluids from two or more sources that are mixed together in the first or second chambers 112, 114 before traveling to the mixing chamber 144. Moreover, elements described with one embodiment may be readily adapted for use with other embodiments. Therefore, the invention, in its broader aspects, is not limited to the specific details, the representative apparatus and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicants' general inventive concept. 

We claim:
 1. A pump comprising: a housing; a diaphragm located within the housing; the diaphragm separating the housing into a first chamber and a second chamber; a first one-way inlet valve for allowing a first fluid into the first chamber; a first one-way outlet valve for allowing the first fluid out of the first chamber; a second one-way inlet valve for allowing a second fluid into the second chamber; a second one-way outlet valve for allowing the second fluid out of the second chamber; an actuator connected to the diaphragm; wherein movement of the actuator in a first direction causes the volume of the first chamber to contract and causes the first fluid to be expelled from the first chamber and causes the volume of the second chamber to expand and draw in the second fluid through the second one-way inlet valve; and movement of the actuator in the second direction causes the volume of the first chamber to expand drawing the first fluid past the first one-way inlet valve into the first chamber and contracts the second chamber causing the volume of the second fluid to be expelled through the second one-way outlet valve.
 2. The pump of claim 1 further comprising a mixing chamber for receiving the first fluid and the second fluid.
 3. The pump of claim 2 further comprising an outlet nozzle for dispensing the mixture of the first fluid and the second fluid as a foam.
 4. The pump of claim 1 wherein the actuator passes through a wall of the pump.
 5. The pump of claim 1 wherein the actuator is a piston.
 6. The pump of claim 1 wherein the diaphragm is an elastomeric element.
 7. The pump of claim 1 wherein the diaphragm is a rubber element.
 8. The pump of claim 1 further comprising a first reservoir for holding the first fluid and a second reservoir for holding the second fluid.
 9. A dispenser comprising: a dispenser housing and a pump system; the pump system includes a housing and a diaphragm; the diaphragm separates the housing into two chambers; the diaphragm having a first position that reduces the volume of the first chamber and expands the volume of the second chamber; the diaphragm having a second position that expands the volume of the first chamber and reduces the volume of the second chamber; wherein movement of the diaphragm to the first position causes fluid to be expelled from the first chamber and fluid to be drawn into the second chamber; and wherein movement of the diaphragm to the second position causes fluid to be expelled from the second chamber and fluid to be drawn into the first chamber.
 10. The dispenser of claim 9 further comprising a mixing chamber for receiving the first and second fluids.
 11. The dispenser of claim 9 wherein the pump reciprocates at a speed greater than about 60 cycles per minute.
 12. The dispenser of claim 9 wherein the actuator comprises a piston.
 13. The dispenser of claim 9 wherein the actuator passes through a wall of a housing of the pump.
 14. A method of creating a foam comprising: providing a pump having a first chamber and a second chamber separated by a diaphragm; providing a first fluid comprising an acid and a second fluid comprising a base; moving the diaphragm to a first position causing the first fluid to be pumped to a mixing chamber and the second fluid to be drawn into the second chamber; and moving the diaphragm to a second position causing the second fluid to be pumped to the mixing chamber and the first fluid to be drawn into the first chamber; wherein a chemical reaction occurs between the first fluid and the second fluid that causes the formation of gas and the mixture is expelled as a foam.
 15. The method of claim 14 wherein at least one of the first and second fluids contains a wax.
 16. The method of claim 14 wherein operating the pump from the first position to the second position and back to the first position occurs at rate that is greater than about 60 cycles per second.
 17. The method of claim 14 comprising operating the pump at a frequency sufficient to agitate the first and second fluids in the mixing chamber.
 18. A refill unit for a two fluid foam dispenser comprising: a first reservoir and a second reservoir formed between two sheets of material; a first tube extending to the first reservoir and a second tube extending to the second reservoir; the first tube and second tube at least partially surrounded by the sheets of material; a mixing chamber, wherein the mixing chamber is in fluid communication with the first and second tubes; and an outlet nozzle downstream of the mixing chamber; wherein a first fluid from the first fluid reservoir and a second fluid from the second fluid reservoir are combined in the mixing chamber and form a foam that is dispensed out of the nozzle.
 19. The refill unit of claim 18 further comprising a first valve and a second valve having a sufficient cracking pressure to prevent inadvertent discharge.
 20. The refill unit of claim 18 further comprising a roller actuator, wherein the roller actuator is configured to compress the first and second tubes through at least a portion of travel that includes sheet material. 